There exist many hazardous waste materials that are difficult to dispose because of the possibility that they may contaminate the environment. Such hazardous materials include compounds like radioactive elements, heavy metals, sulfur, and halogens. These materials can be commonly found in many wastes, products, and compounds.
Typically, such hazardous waste is either buried or burned, both of which can be costly processes. Accordingly, it is desirable to process such wastes into materials that are more easily disposed of at lower costs. A large number of methods for treatment of such materials are known.
In the past, waste materials containing sulfur and halogens have typically been treated through processes like cementation, pyrolysis and incineration. Incineration processes Incinerators and related processes that utilize open-flame combustion fall under stringent and comprehensive air pollution laws that typically render the incinerators economically infeasible.
Pyrolysis methods are generally more flexible and can be used for the treatment of most waste materials. However, secondary waste streams that are generated from these processes, such as particulate waste, large volumes of scrubber solutions or dried salts that are difficult to solidify, and off gases, still present process and disposal issues that must be addressed. For example, the presence of sulfur-containing compounds in a vitrification melter can cause a molten sulfur salt pool to accumulate on top of the molten inorganic residue (glass). This pool causes high corrosion rates for the melter equipment. The pool can also have a high electrical conductivity, which causes short-circuiting of the heating electrodes in the melter. Additionally, potentially explosive conditions can result if large quantities of water contact the molten sulfur salt pool.
There remains a need for a process that does not have the limitations and shortcomings of the above described methods for processing radioactive waste materials comprising sulfur-containing compounds and/or halogen-containing compounds.
The description herein of certain advantages and disadvantages of known methods is not intended to limit the scope of the embodiments.